Details for the main summary of this event were acquired from the following sources:
- Atlas of the Edmonton Tornado and Hailstorm: A Decade of Research, Robert B. Charlton, et. al. (Will be referred to as the Atlas in the summary)
- Tornado: A Report, Alberta Public Safety Services (APSS)
- Black Friday: The F4 Edmonton, AB Tornado of July 31, 1987, Highways and Hailstones
- The Edmonton Journal Newspaper
A line of thunderstorms formed along the foothills of Southern Alberta before 12pm MDT. As the storms strengthened and moved northward, a “severe weather watch” was issued at 140pm MDT. This included the Edmonton area. The line was moving at a speed of 70 km/h (43 mph). Ahead of this line, an individual cell formed near Leduc. This is approximately 20 miles south of Edmonton. A call came into the weather office just before 3pm MDT reporting a “rope-like funnel” had been seen near Leduc.
The caller was Tom Taylor, a Leduc pharmacist. I found the description of what he saw on his own website for Bellweather Kennels Canada. From Taylor, “Suddenly a thin translucent funnel flashed onto the landscape. I could see through it. Material was radiating out from the funnel and upward at a 45 degree angle, in a brownian-like movement, and disappeared into the cloud base. The funnel connected the cloud base to the ground below. This was a tornado. It had touched down inside the eastern edge of Leduc, Alberta. Then it was gone, just as suddenly. It has lasted only ten seconds.”
This call along with the observance of a strengthening cell on radar led to the issuance of a tornado warning that included Edmonton. Taylor continues his account after the phone call ended. “I returned to the loft upstairs. By this time the lowered cloud was North East of the house. As the cloud traveled toward Beaumont, Alberta, the belly slumped, spitting out a huge funnel which slammed onto the ground below. I watched as the tornado churned along, exploding buildings it encountered. The tornado eventually turned northward where it raked the eastern edge of Edmonton, Alberta, causing death and destruction. And as they say, the rest is history.”
And it would certainly be one for the history books. The deadliest tornado ever recorded in Alberta was heading north toward its capital city. The supercell that had produced a brief rope tornado near Leduc had now spawned “The Black Friday” twister. It would create a continuous damage path for the next hour.
Per the Atlas, “between 1500 and 1605 MDT, the tornado, moving from south to north through east Edmonton, left a continuous damage swath 37 km in length, ranging from 100 m to more than 1000 m in width.” Between various sources there are some discrepancies regarding the path length. Officially, the Canadian Tornado Database lists a length of 30.8 km (19.14 miles). The APSS assessment lists a length of 40 km (24.85 miles).
The tornado tracked through southeast Mill Woods. It was observed as a broad cone with multiple vortices. The fire department rescued 15-20 victims from collapsed buildings and damaged vehicles. Some were treated for serious injuries. 32 homes were damaged. Just south of Mill Woods there were three homes destroyed and two had major damage. This area received some of the largest hail during the event with some stones reaching 10 cm (nearly 4 inches) in diameter.
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